Borehole instrument

ABSTRACT

THE PARTICULAR EMBODIMENT DESCRIBED HEREIN AS ILLUSTRATIVE OF ONE FORM OF THE INVENTION UTILIZES A MOTION SENSING DEVICE TO CONTROL THE OPERATION OF A TIMING CIRCUIT IN ADOWNHOLE WELL TOOL. THE ABSENCE OF MITION WHICH IS INDICATIVE OF THE TOOL BEING AT ITS OPERATING POSITION, PERMITS AN ELECTRONIC COUNTING CIRCUIT TO INITIATE SIGNALS FOR OPERATING THE TOOL. THE TOL IS PREVENTED FROM BEING OPERATED IN A NEARLY HORIZONTAL OR INVERTED POSITION EVEN IN THE ABSENCE OF MOTION. THE TOOL MAY BE REPETITIVELY OPERATED BY ALTERNATELY CAUSING MOTION AND THE ABSENCE OF MOTION OF THE TOOL. A PHOTOGRAPHIC RECORDING DEVICE MAKES A RECORD OF SUCH REPETITIVE OPERATION.

I United States Patent I 3,5 3,90

[72] Inventor James M. Lindsey lSol References Cited 5 UNITED STATESPATENTS P 6.l9l 2584983 2/1952 Butterworth 346/7)( [22] Filed Nov. l5,I968 2,756,5l I 7/!956 Young 33/2055 [45) Patented June 28,197] [73]Assignee Sperry Sun Well Surveying Company 30O4'6l3 0/196! Murpheym75/45 3,316,651 5/1967 Godbey 33/205 Sugar Land, Tex.

Primary Examiner-Joseph W. Hartary Attorneys-George L. Church, Donald R.Johnson, Wilmer E.

McCorquodale, Jr. and John E. Holder ABSTRACT: The particular embodimentdescribed herein as BOREHOLE INSTRUMENT illustratige of one forml (iiithe invention util zes a motion I l Chums 3 Drawing Figs. sensing eviceto contro t e operation o a timing c rcuit in a downhole well tool. Theabsence of motion which is indicative [52I U.S.Cl 346/33, of the toolbeing at its operating position, permits an elec- 346/7, 346/107, 33/205.5, 175/45 tronic counting circuit to initiate signals for operating thetool. [5] 1 Int. Cl ..E2lb 47/022. The tool is prevented from beingoperated in a nearly horizon- GOld 9/42 tal or inverted position even inthe absence of motion. The [50] Field of Search 346/ I07 tool may berepetitively operated by alternately causing mo- (W). 33 (Well), 7;33/205.5 (P); 95/] 1 (HC); ZSO/(lriquired), 83.6 (W); l75/45, 44;l66/255 lion and the absence of motion of the tool A photographicrecording device makes a record of such repetitive operations 44 46 48.4 "J Mono" -q nz iz r on QAASEE H COUNTER DETECTOR AMPLIFIER RESET l T52 42 i 49 47 50 POWER COUNTER TIME SUPPLY RESET BASE 6| 3i l e2 33 e4SOLENOlD SOLENOlD M DRlVER -u SWITCH SOLENOID CH AMPLIFIER CIRCUIT TOClRCUlT L 56 5| SKIP AND CONTROL GATE 5 6 5a is LAMP LAMP DRIVER SWITCHLAMPS AMPLIFIER CIRCUIT PATENTEUJUNZBIHTI 3,588,908

MOTION TIME MOT'ON DETECTOR BASE COUNTER DETECTOR AMPLIFIER RESET I l JL 1 42 l 49 j I I POWER COUNTER TIME 50 SUPPLY RESET BASE SOLENOIDSOLENOID MERCURY DRIVER v SWITCH Sol-5N0") SWIT AMPLIFIER CIRCUIT T0CIRCUIT 66 5| SKIP AND k V J I LAMP I LAMP 7 DRIVER SWITCH LAMPSAMPLIFIER CIRcuIT F IG. 2

FIG. I ATmR/w Y BOREHOLE INSTRUMENT BACKGROUND OF THE INVENTION Thepresent invention pertains to a borehole tool and more particularly to adevice for operating a borehole tool upon its reaching a downholeposition by utilizing the presence and absence of motion of the tool.

When making drill holes in the ground, particularly drill holes whichrun partly through rock and partly through less consolidated earthlayers, it often happens that the dip or inclination of the drill holeto the horizontal plane as well as the direction of the hole will varyquite considerably at different depths of the hole. In many cases,therefore, it is very important to determine the existing deviationsfrom a desired inclination and direction and in addition it is oftendesirable to survey the complete traverse of an uncased hole. One suchsituation occurs when it is desirable to determine the true verticaldepth of a hole in order, for example, to locate a geological formationrelative to the well depth. A complete survey of the borehole traverseis also desirable for the purpose of a check survey, used to determineif a directionally drilled hole is located at its intended positionHowever, the most common use for the so-called multishot" directionalsurvey is to determine the exact bottom hole location or the path of thewellbore. A survey of the path may be used to pick out an optimum pointin the wellbore to start the deflection of a directionally drilled hole.Defining the bottom hole location would have applications to manysituations as, for example, to determine where the hole bottom islocated relative to a stratigraphic feature of a formation, or even forlegal purposes.

One apparatus which has been used for the purposes outlined above istermed a multishot magnetic directional survey instrument. Such aninstrument is used to obtain a running record of the inclination and thedirection of inclination at various depths in a borehole. The instrumentmay be used for the purpose of orienting a hole in directional drillingoperations, and also to chart the course of boreholes from surface tototal depth during a normal drilling operation. The directional featuresof the instrument consist of a magnetic compass. The inclination unit isa form of inverted plumbob. These two features are combined into asingle compass angle unit which may be available in various ranges ofdegrees of inclination. The compass angle unit is normally comprised ofa floating magnetic needle designed so that its directional and angularpositions may be simultaneously photographed and recorded on a filmstrip. A movie camera unit in the instrument makes a permanent record ofthe compass angle unit reading as it traverses the borehole. Electricalpower to operate lamps in the camera unit may be furnished by batteriesor by a conductor cable suspending the instrument from the earth'ssurface. An electrical circuit for activating the lamps is controlled bya clock which allows for a predetermined exposure period of the filmframes for recording the inclination and direction of inclinationindicated by he compass angle unit. The clock mechanism also providesfor advancing the film and causing a delay of, for example, secondsbetween frames of film wherein the lamps are shutoff.

In operating such an apparatus, a desired compass angle unit is selectedand assembled, and the batteries and films are loaded with the clockbeing set for the appropriate delay time between frames. The camera isthen started, the instrument is assembled into a protective casing, andlowered on a wire line into an open hole or positioned in a nonmagneticdrill collar at the lower end of the drill stem. Alternatively, theapparatus may be go-deviled into a nonmagnetic drill collar andretrieved with an overshot or by pulling the drill string.

In any event, while the tool is being run into the well, the camera isoperating to take picture records of the compass angle unit every 20seconds. Since the instrument is in constant motion during this eriod,the film exposure will be blurred and unusable as a record of theinstrument reading at that depth.

After the tool reaches a surveying station and becomes relatively still,the images recorded on the film will be intelligible. Therefore, theinstrument will be left at such position for a period long enough toexpose a desired number of frames with each frame exposure or readingbeing a check on other readings at the same location. After sufficienttime has elapsed to make, for example, five exposures, the tool is movedto a second recording station whereupon the procedure is repeated. It isagain pointed out that during the time the instrument is being moved toanother station, the camera is continuing to take pictures ofthe compassangle unit. In order to correlate the exposures with the depths of thevarious stations, it is necessary to keep accurate records as to thetime lapses, i.c., start and stop of the instrument motion and time onand between each station, from the moment the camera is started, whenassembling the instrument until the last station is recorded and thetool is retrieved. In addition, the timing control or clock mechanism inthe instrument must be accurate so that the time between and duringexposures is accurately determinable in order to facilitate the timedepth correlation. The time depth correlation requires considerableattention from the operator as well as time after the survey is run tomake the correlation.

Since much of the exposed film has recorded "moving pictures, that is,images of the instrument while motion is occur ring, a large amount offilm is necessary in order to obtain a much less amount of usablerecords. The size of well tools, particularly those run inside drillpipe, is critical, and thus an adequate film supply can become a problembecause of the limited space available for film magazines.

SUMMARY OF THE INVENTION With this and other objects in view, thepresent invention contemplates an apparatus for programming theoperation of a downhole operated well tool. The apparatus includesposition and motion sensing devices, each of which can prevent theoperation of a timing mechanism. When the tool is in a substantiallyupright position, power is supplied to the programming circuit.Thereafter, in the absence of motion, a motion detector means causes atiming mechanism to operate the tool on a repetitive basis. When thetool is moved, motion is sensed, and a function of the tool ceases tooperate. When motion again ceases, the tool is reoperated. A signal isproduced to make a record of the motion of the tool after each operationof the tool.

A complete understanding of this invention may be had by reference tothe following detailed description, when read in conjunction with theaccompanying drawings illustrating an embodiment thereof.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a schematic view of aninstrument for utilizing principles ofthe present invention;

FIG. 2 is a schematic diagram of an electrical circuit embodyingprinciples of the present invention; and

FIG. 3 shows a motion detecting device for use with the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIG. 1 ofthe drawings, a schematic view of a well surveying instrument includesat the upper end of the instrument a power supply section II which maybe in the form of a battery pack or a power supply circuit receiving itspower from a conductor cable (not shown) extending to the surface.Immediately below the power supply housing, is a control circuit housing12 which contains the electrical circuitry for operating the surveyingapparatus. The lower section l3 of the tool houses the survey instrumentand includes a camera unit and surveying instrument. The camera unit hasa film supply reel 14, ratchet driven takeup reel to, and camera shuttersystem I7 positioned in the upper end of housing section I3. A solenoid64 has a ratchet driver 20 connected to its armature for driving thefilm taltcup reel and shutter. liach energization of the solenoidadvances the film one frame. The solenoid 64 is operated by the circuitin housing I2. Below the film and shutter system is a lens I! with lampsIll being positioned below the lens. A glass disc 19, which contains areticle in its center is positioned below the lamps in the housing. Theglass disc also forms the upper end ofa chamber 2| containing a fluid inwhich a compass angle um! 22 is pivotally floated. lndicia on the head24 of the compass angle unit provides a visual indication of thedirection and inclination of the tool housing. The buoyancy of the fluidin the chamber maintains the compass angle unit in a vertical positionon its pivot 23 throughout various positionings of the instrumenthousing in the wellbore.

In the operation of the instrument described above, the electricalcircuit is activated at some instant of time to energize the lamps Ill.The light emanating therefrom is directed through the glass disc I9 ontothe head 24 of the compass angle unit 22. The compass angle unitincludes a magnetic needle which is oriented in a north-south direction.in addition, the unit is permitted to tilt on its pivot 23 away from thelongitudinal axis of the tool, to provide an indication of the tool inthe wellbore. Light impinging upon the head 24 of the unit is reflectedback through the glass disc 19 and the reticle thereon, through the lens[5, and on to the film positioned in shutter system [7. Therefore, whilethe lamps are lighted, the film is exposed to the image presented by thecompass angle unit head and the reticle engraved on the glass. Therecord of this image provides an indication of the direction andinclination of the borehole. After a predetermined exposure time, thecontrol circuit shuts off the lamps I8 and also advances the film oneframe, and the cycle is repeated.

The present invention pertains to a device for initiating and timing theoperation of an instrument such as a directional surveying instrument,however it is pointed out that the timing or programming circuitdisclosed herein would have application to other types of wellboretools.

The apparatus of the present invention incorporates in an electricalcircuit, a motion sensing device such as the one shown in FIG. 3 of thedrawings. The apparatus of FIG. 3 includes a conductive housing 26. Thehousing is open at one end for receiving a plug 27 made of a conductivematerial. The plug is separated from the housing by an insulator 28 toprovide a pair of electrically insulated conducting surfaces. The plug27 has an upwardly extending portion 29 which is also insulated from thehousing, and which has a pivot point 31 at its upper end. The spacebetween the upper end of the upwardly extending portion 29 and the topof the housing 26 forms a chamber 32 which is sized to receive a ball33. The ball is constructed of chrome or other such electricallyconducting material. The inside wall surfaces 34 of the housing 26 whichsurround the chamber 32 are preferably roughened or threaded to providea multiplicity of contacting points thereon which renders the devicemore sensitive to motion thereof. The ball is received within thechamber 32 and, in a motionless condition, the ball will rest on thepivot point 3] and against the inside roughened surfaces of the wall 34of the housing. In this condition, the ball 33 establishes a conductingpath between the plug 27 and the housing 26 which are furnished withrespective contacts and conducting wires 36, 37. The roughened threadedwalls of the housing form a more elastic surface to increase motionofthe ball and thus sensitivi ty of the motion detector. As the ballrests upon the pivot 3| in the chamber 32, a slight movement of theinstrument causes the ball to move on the pivot from one wall portion tothe other, thus intermittently making and breaking a conducting path inan electrical circuit including wires 36 and 37.

Referring now to FIG. 2 of the drawings, the circuit for operating theapparatus includes a mercury switch 41 which is positioned electricallybetween the battery power supply 42 and the remaining portions of thecircuit. The mercury switch is arranged so that when the apparatus is inan inverted or near horizontal position, no power is supplied from thebatteries to the circuit. This permits make up and assembly of the toolprior to delivery of the tool to the well location. Upon move ment ofthe tool from a horizontal position to a more vertical upright position,the switch is operated to supply power from the battery or other source42 to the circuit of FIG 2.

The circuit of FIG 2 includes a motion sensing or detecting device 43such as the one described with respect to H0. 3 The motion sensingdevice is arranged in the circuit to control the output of a motiondetecting amplifier 44. in the absence of motion the detector 43 closesa circuit path to cause the amplifier to produce an output for supplyinga control signal to various other components in the system. The signalfrom the amplifier 44 is fed to a time base reset circuit 46 which inturn resets a time base or a low freq uency oscillator circuit 47 tozero time each time motion is detected, and causes the oscillator toproduce continuous output signals. The output of the oscillator is fedto a counter 48, which is in the form of an AC flip-flop in ripple countconfiguration.

A counter reset circuit 49 also receives an output signal from themotion detector amplifier 44. Thus when there is motion in the system, atransistor circuit in the counter reset 49 is shorted which in turncauses the ripple counter 48 to be placed in its original or start countcondition.

The counter 48 is arranged so that after 20 pulses from oscillator 47have been received by the counter, the counter will produce a signalthrough a first output line 50 to "and" gate 5]. Another output line 52is at the same potential to cause the gate to operate upon receiving theinitial signal through line 50. Gate 5! is operated to provide power toa driver amplifier 56. The output of amplifier 56 operates a lampswitching circuit 58 or power switch to energize lamps IS in theinstrument. The energization of lamps l8 causes cs posure of the filmfor the time period during which positive signals are provided from bothoutputs 50 and S2 of the counter to the "and" gate 51. Upon the lapse ofa predetermined amount of time, for example 2% seconds, a second signalis produced by the counter through output line 52 to the "and" gate 51.This second signal from counter 48 through line 52 is of an oppositepotential from line 50, thus the gate closes and the lamps .8 are turnedoff. The operation of the circuitry just described permits exposure ofthe film for the 2.5 seconds.

As the counter continues to operate, after another predete rmined periodof time, an output 61 from the counter 48 produces a pulse which is sentto a solenoid driver amplifier 62 which in turn activates a solenoidswitching circuit 63 to operate the solenoid 64. Operation of solenoid64 advances the film in the camera one frame. After the solenoid hasfired, the counter automatically resets to zero to begin countin againas long as pulses are being received from the time base. The output 6|from counter 48 may be arranged to produce an output signal to thesolenoid driver at the beginning of the counter operation rather than atthe end of the count operation, with the effect being the same. In anyevent, after the solenoid is operated, the counter will continue tooperate or recycle, whichever the case may be. After a lapse of anotherpredetermined period of time, for example 20 seconds, a signal isproduced again through output 50 of the counter to initiate operation ofthe lamps. After 2.5 seconds the opposite polarity output of line 52causes the and gate to be interrupted and thus deenergizes the lamps 18.This sequence of operation is continued until the apparatus is placed ina horizontal position, or inverted, wherein the mercury switch 4ldeactivates the circuit, or motion is detected by the motion detector43. Upon such motion being detected, the time base 47 of the counterwill reset to zero as described above, and in addition, a counter resetwill cause the counter to return to its initial position.

In addition to the circuit operation described above, the motiondetector amplifier 44, upon receiving an indication of motion, providesa signal to a DC flip-flop, which is termed skip control 66. During thenormal operation of the apparatus, when the output 52 of the counter 48causes the "and" gate Si to deactivate the lamp, this lltt't'llltttllamp trll' signal i ent by means of amplifier circuit 56 lo the litflip-flop or strip control 66 to rettet the output of slttp control 66to zero. The flip-flop 66 will remain in this t.'tllltlllltl|l until asignal it sent from the motion detector amplilier to the flip'llop 66.Thus. the strip control llip-llop will berineffeetive to operate thesolenoid until a signallrom the motion detector amplifier changes theoutput thereof. in the meantime, tlte solenoid amplifier will beoperated only by a signal from the output H of the counter. Therefore,each time after tlte lamp is energised and then dccnergized. and thedetector 43 detects motion. the solenoid 64 is actuated for advancingthe film one frame Since after normal operation of lltc counter andeaptttture of the frame the solenoid has already operated, this causesthe skipping ttfone uncrportcd fratpe in the film strip to provide anindication on the film strip thitt motion has tulten place. As will hehereinafter described. this provides a signal to the person interpretingthe film as to movement between the stations in the surveying ufawellhorc.

in the operation of the apparatus ust described, the instru ment isloaded with film, the tool is assembled, whereupon it may be placed inan inverted or horizontal position for trans portation to the well site.The mercury switch 4| prevents tlrrapplication of power from powersupply 42 to the control ctr cuil. When it is time to run the instrumenttrtto the well, thttool is raised to a substantially vertical uprightposition. whereupon the switch 4| is closed and ower is supplied to thecontrol circuit. However, during the period that the tool is beinglowered into the wcllborc, whether by wire line or go deviling. the toolis in constant motion. The motion detector is therefore effective tomaintain the control circuit in an unoperated condition. Uponrcachingsurvey depth. the tool becomes quiet," and the motion detector completesa circuit to the amplifier 44. Amplifier 44 sup lies a signal to timebase reset 46 which sets the obclllalor at rcro time and begins theoperation of the oseillatorilfl. As the oscillator sends pulses to thecounter 48. the counter begins to step or count. After counting forseconds, a signal is generated on output line 50 which matches theoutput of line 51 whereupon "and gate St is operated. Opet'ilionol' gatcSt through the lamp circult activates lamps l8. After a lapse of 2.5seconds, line 50 or 51 changes polarity and closes the gate 5 l. Uponthis happening, a reset signal is sent from the driver amplifier 56 tosltip control 66 which changes the condition of flip-flop 66 to zerooutput. After another predetermined count, a signal through line 6|drives the amplifier 62 to actuate solenoid 64. This advances the filmone frame to condition the system for a repetirive cycle of operation.

The above sequence of operation is continuously repeated until the toolis moved to another station. Upon movement thereof. the motion detectorinterrupts its output to the amplitier 4. which in turn interrupts itsoutput to the strip control flip-flop 66. This changes the condition offlip-flop 66 and causes a signal to be sent to solenoid amplifier 62.This in turn causes the solenoid to actuate and advance the film oneframe. Since the lamps are now off, the resulting unexposed frameprovides an indication that the tool has been moved between stations.

At the same time the interruption of the signal to the motion detectoramplifier causes the reset circuits 46 and 49 to short thus resettingthe oscillator 47 and counter 48 to a zero rinse reference.

It is apparent that the film record of a survey taken with the abovedescribed device will be adequately referenced as to its stops betweensurveying stations and that therefore accurate time depth correlationrecords need not he made. instead, the operator must merely record thell -;-th of each surveying station. in addition, since it is no longernecessary to record time lapses between the surface and the firststation and between subsequent surveying stations, an accurate record ofsuch time lapses is not critical and therefore the dsi'grt 6f the timingequipment may be moresirnpie and less costly as a result.

While particular embodiments of the present invention have been shownand described. it is apparent that changes and modifications maybe madewithout departing from this inven tion in its broader aspects, andtherefore. the aim in the appended elaims is to cover all such changesand modifications as fall within the true spirit and scope of this invention.

Ielttim:

l. in an apparatus for programming the operation of a downhrtlc welltool. motion detector means for providing a signal indicative of thepresence of motion; counting means for providing signals indicative ofpredetermined trrne lupxe intervals; well totrl means operative inresponse to at letrst one of said counting means signals; means forstarting said t'outtttrig means in the ttltttcttcc oltt sign-til fromsaid motion detector to operate ttaitl well totrl means, means forstopping sutd counting mcuntt upon the occurrence of as signal frontsand mo tion detector means to stop the operation of suit! well toolmeans, and means for restarting said counting means tn the absence of attigrtal from said motion detector to tcslztrl \Zfllul well toolmcalts 1. The apparatus of claim I and lurtitcr including roe-urn forpreventing the operation ul said well tool means when the .rt lttudc ofsaid well tool ntcurts IS other than that normall ac curing during itsoperation I a wellborc 3 The apparatus of claim I and lurthcr includingmt'tttn for roviding an indication rcrtdttl lc .rt llrc ssarFsg, oi tinoccur rcncc of a signal from suttl llllrlttrlt tlt'lto l ll wersind\uglf s! means is operated 4 lit a wcllhurc tool, apparatus lotprogramming the opera tron ol the tool upon positioning of the tool atits operating position in the wellborc. which apparatus comprises. meansfor sensing the presence of motion of the well tool; means responsive tothe absence til motion for initiating operation of the well tool in thewcllhorc; and means responsive to the presence of such motion forstopping the operation of the well tool. said initiating means beingeffective to restart the operation of said well tool in the absence ofmotion and continuously operate said well tool in the absence of suchmotion for an indefinite period of time.

5. The apparatus ofclaim I and further including means for providing arecord of the stopping of the operation of the well tool.

6. In an apparatus for initiating the operation of a well tool function:counting means for initiating signals to start and stop an operation ofthe well tool alter a predetermined time lapse from a zero timereference motion sensing means for prevent ing operation of the welltool while said tool is in motion; time base means responsive to theabsence of motion for initiating operation of said counting means; meansresponsive to the presence of motion for resetting said counting meansto a zero time reference; and means responsive to a signal from saidcounting means for recording an event indicative of the operation of thewell tool.

7. The apparatus of claim 6 wherein said counting means is comprised ofan AC flip-flop circuit in the configuration of a ripple counter.

I. The apparatus of claim I wherein raid means for initialing operationof said counting means includes a low frequency oscillator circuit whichfeeds pulses to said ripple counter.

6. in a wellborc surveying instrument having a lens. lttlttp, and filmadvance system for photographing an instrument indicative of weliborcconditions, means for initiating and stopping the application ofelectrical power to the lamps and for advancing film in the system.which means comprises: motion detecting means for providing a signal inthe absence of motion of the instrument; means responsive to a signalfrom said motion detecting means for providing timed output pulsea;counting meant-operated by said timed output pulses and producing first.second. and third spaced output signals at tinted intervals from zeroreference time; gate circuit means operative in response to said firstand second output signals for Initiating and stopping the application ofpower to the lamps; and means responsive to said third output signal foroperating the filth advancing means.

